1. Field of the Invention
The present invention relates to a method and apparatus for driving a servo system which positions a structure which vibrates by a reaction force of a drive force generated in a positioning operation while suppressing a residual vibration of the structure.
2. Description of the Related Art
In JP-A-60-171512, means is disclosed to suppress a structure vibration by utilizing a vibration inertia force of a load weight and using a servo mechanism. JP-A-60-231205 discloses a method for suppressing a vibration of a mechanical system without adding a separate vibration suppression device. In this method, a mechanical system in a positioning control system is modeled by an electrical circuit, the model is arranged in parallel to the control system and a signal therein is supplied to a main loop to suppress a mechanical vibration of a load.
However, in the first prior art technique, although a vibration suppression effect is attained, a separate vibration suppression device is required. As a result, the system is complex. In the second prior art technique, no separate vibration suppression device is required and the system construction is simpler, but there is no assurance that a positioning operation is attained in a short time. Further, if there is an error in the electrical circuit model of the mechanical system, the vibration suppression effect is reduced.